P2GS: Physical Prior-guided Gaussian Splatting for Photometrically Consistent Urban Reconstruction
This work addresses the photometric inconsistencies and artifacts in static backgrounds caused by varying camera exposures and dynamic illumination in real-world driving scenarios when using conventional 3D Gaussian splatting. To resolve this, we propose the first Gaussian splatting framework that integrates a physical imaging model, enabling joint disentanglement of a view-invariant linear HDR radiance field, per-view exposure scales, and tone-mapping functions from only LDR images. By incorporating relative exposure consistency constraints and HDR-domain radiance regularization, our method achieves cross-view photometrically consistent reconstruction without requiring HDR supervision. Evaluated on both real and synthetic driving datasets, the approach attains state-of-the-art LDR reconstruction quality while significantly improving photometric consistency, reliability of exposure normalization, and physical plausibility of recovered illumination.